US2694000A - Hydrator for lime and the like - Google Patents

Description

V. J. AZBE HYDRATOR FOR LIME AND THE LIKE Nov. 9, 1954 4 Sheets-Sheet 1 Filed April 5, 1952 FIG.

Nov. 9, 1954 v. J. AZBE HYDRATOR FOR LIME AND THE LIKE 4 Sheets-Sheet 2 Filed April 5, 1952 FIG. 3.

Nov. 9, 1954 v. J. AZBE HYDRATOR FOR LIME AND THE LIKE Filed April 5. 1952 4 Sheets-Sheet I5 Nov. 9, 1954 v. J. AZBE HYDRATOR FOR LIME AND THE LIKE 4 Sheets-Sheet 4 Filed April 5. 1952 Q Emil sion of United States Patent Ofitice 2,694,000 Patented Nov. 9, 1954 2,694,000 g p HYDRATOR FOR LIME AND THE LIKE Victor J. Azbe, Webster Groves, ,Mo., assiguor to Azbe Corporation, Clayton, Mo., a corporation of Missouri This'invention relates to hydrators for lime and the like, and more particularly to automatic continuously recycling apparatus of this type. r

ong the several objects of the invention maybe noted the provision of an automatic lime hydrator which will produce a consistently good hydrated. lime from either good or poor raw material (quicklime); the provia hydrator of the class described which operates continuously without excessive attention, 'and without the escape of such quantities of 'dust and steam as ordinarily constitute a hazard or nuisance and loss in connection with apparatus of this class; and the provision of apparatus of this class which conveniently lends itself to instrumental control. Other objects will be in part apparent and in part pointed out hereinafter.

The invention accordingly comprises the elements and combinations of elements, features of construction, and

arrangements of parts which will be exemplified in the structures hereinafter described, and the, scope of which will be indicated in the following claims.

In the accompanying drawings, inwhich one of various possible embodiments of theinvention'is' illustrated,

Fig. 1 is an isometric view of a hydrator embodying the invention, parts beingbroken away;

Fig. 2 is 'a right-end view of Fig. 1;

Fig. 3 is a left-end view of Fig. 1;

Fig. 4 is a top plan view of Fig. 1; I I

Fig. 5 is a diagrammatic sectional assembly view, being rearranged for clarity,with flowlines illustrating certain improved functions; and, r r

Fig. 6 is a cross section taken on line 6 6 of Fig. 5.

Similar reference characters indicate corresponding parts throughout the several views of the drawings,

Briefly, the invention consists in a container intowhich premixed quicklime and water are fed. 'This container has an adjustable discharge opening for maintaining an inside level of material. The container, which'is preferably circular, has a bottom which'slopes from the periphery toward a central [annular portion heavier granular material toward said The central portion is'preferably flat. v

Within the container is a rotor composed of a system of depending circular baflles having overflow slots in their sides. These slots allow progress of lighter hydrated material from the center toward the periphery and to said discharge opening. The bafiies have lower plows arranged to bias the heavier granular material toward the flat central portion. discharge device. A partial'vacuum is induced in the container in order to draw in air for cooling. and delivery with generated steam and dust to 'a wet dust collector wherein the steam is partially condensed and the dust removed from the air. may be returned to the bottom of the circular container to provide additional control over the conditions, such as rate and temperature of hydration.

Referring now more particularly to the drawings, the circular container is shown at numeral 1, being mounted upon standards 3. It has a circular periphery 5 and a cover 7. Its bottom has a flat central annular sump portion 9 and arconical and downward slope 11. Centrally there is a cylindric dam 13. Through this dam and the cover7 extends a drive shaft which is driven through a gear-reduction unit 19 by a motor 17. For example, the shaft 15 may for g'ravitating central portion.

be'rotated on the order of 10 R. l? ."M. although this is notto be taken as limiting.

If desired, the air-vapor stream periphery forming an inward parts Below the central portion is a waste The motor 17 and reduction unit 19 are mounted upon a superstructure 21, carried upon standards 23. Suspended from the superstructure 21 is a premixer 25, constituted by a trough 27 in which are shafts 29 carrying interdigitating mixing paddles 31. The shafts are connected for 1:1 rotation by meshed gears 33. One of the shafts is driven from a motor 35 through a gear-reduction unit 37 and a chain drive 39. At 41 is shown an inlet opening for the premixer 25 and at 43 an opening leading to the container 1. At 45 is shown an inlet hopper for raw material (granular quicklime) from which the material is moved to the inlet 41 bymeans of a belt conveyor 47. The conveyor is driven from a motor 49 through a belt drive 51 anda gear-reduction unit 53. The function of the premixer 25 is to advance the raw material from the inlet41 to the opening 43 of the container 1 and thoroughly to premix it with water. Water is introduced through nozzles shown at 55 and 56 (Fig. 5).

Attached to the rotary shaft 15 inside of the container 1 is a rotor or stirrer 2 constituted by a hub 57 from which extend radial arms 59, these arms supporting depending circular bafile plates numbered 61, 63, and 67, progressing outward from the center. The lower circular rims of these baflles are near (but spaced from) the bottom parts 9 and 11. The inner baflle plate 61 is not perforated. Baflies 63, 65 and 67 are perforated by spaced and essentially rectangular openings 69, 71, 73, respectively. There are four openings 69, each 31 inches long and 16 inches high. There are eight each of openings 71 and 73, each 36 inches long and 10 inches high. The lower edges 68 of openings 69 are below the lower edges 72 and 74 of open' gs 71 and,73, respectively. On the lower rims of the bafiies 61, 63, 65 and 67 are groups of angled plows 75, 77, 79 and 81. The inner plows 75 are angled to push particles outward, whereas the plows 77, 79 and 81 are angled to push granular materialinward. The plows are adjustable in angle and height (see set screws 82 in Fig. 1 for this purpose). I

The container 1 has an overflow outlet 83, the lower edge of which is on and controlled in elevation by a vertically sliding gate 85. A typical level of material in the container 1, as determined by gate 85, is indicated at L. Exit takes place into a hopper 87, which directs finished hydrate to storage. At 89 is shown an outlet gate for periodically discharging material from the bottom 9 of the container 1. This is on a shaft 90 supported by a bracket 92.and operated by a lever 94. Suitable access openings for the container 1 are shown at 91, and an inspection door at 93.

While it is preferable that the container 1 and baffies 61', 63, 65 and 67 be circular and concentric, it is to be understood that this is not a necessary feature, since they may be relatively eccentric, or suitably polygonal. It is also to be understood that while the particular shapes indicated in the bottom parts 9 and 11 are preferable, other shapes may be employed for these without departing from the invention.

At -is shown a wet dust separator or collector of the centrifugal type having an air outlet 97 in which is a damper 99. Its inlet is shown at 101 (Fig. 4), to which. is connected the outlet of a centrifugal blower 103. The blower is driven from a motor 104 through a belt, drive 106. The inlet of the blower 103 is connected with the. top 7 of container 1 by means of an induction pipe 105. In the induction pipe 105 at the inlet of blower 103 is a water sprayer 107. At the bottom of the collector 95 is a water-condensate pump 109 (driven from motor 116) which collects warm water and entrapped dust from the separator 95 .and through suitable piping 110 may deliver it to inlets 56,

55 and to an additional water inlet 112 in container .1.-

. .3 that additional moisture is introduced into the container '1 at a point to air bind or otherwise condition'the bed.

Operation is as follows:

Raw material is introduced into the hopper 45 in the form; *for example, of granulated quicklime crushed "to a grain size of the order 'of'Ms to /fidnch and including whateverfines occur 'in the-crushing process. Such -material' may vary'in qualitygsuch a's'being soft-burned, hard-"burned, and having more .orless core and extra- -neousmaterial. wSorne'parts of this material require a longertime for hydrationflthan other parts. The material progresses along' the belt'47 through the inlet 41 to the premixer 25. "'-Water is supplied through inlets -56 and'i55. .Premixing occurs, the water being gradual ly= taken up, as water of hydration. The premixed ,material with water enters'the container 1 through the open- -'ingi 43,.;.the1 hydrating process continuing in;' the con- .tainer' with the generation of considerable ,heat and 1 escape of steam andsome dust. More water may be applied through inlet 112. iThe inlet is positioned to dropthexwater'nearthe'center 'of container 1,- where .the larger granules; exist. ,As hydration progresses, the granular material progressively-'disintegrates into finer particles and it is desired to have these in, as powdered, lightand fiocculent astate as;possible for highest quality of product. This result 'is encouraged because the smaller,.lighter and more fiocculent particles tend to rise, whereas the remaining granular particles that exist .at any instant tend to settle to-the. bottom..9, 11' with the aid of.paddle:created downward suction which tends to 'overcornethe carrying'viscosityof the tine hydrated lime vtravelling,laterally toward'the outlet. .The'ydownward- 1y; pointed arrows .113 indicate the" tendency for the heavy granular and.less hydrated material to.-descend.

The .smallersized material tendsto rise, as shown by arrows 115. The 'paths of ;the heaviest granules are indicated by the lower..arrows. 117,..and the path of the lighteshand most completelyhydrated' material, which is in a finished flocculent state, is indicated by .arrows 119. The heaviest material 117 'gravitatesidown the sloping sides of the container under .the bailles andiis aided in moving'toward the center by the. plows'77, 79 and 81. As this heavier material arrives .at the bottom. 9, it is met by.the outwardly'directingplows 75. iThusl the .most granular. and least hydratedmaterial .is retarded .from-.advance. toward the outlet and recycled for additional agitation and hydration, whereas the lighter, completely hydrated particlesgradually rise and .prpgggss throughthe openings 69, '71 and .73 to 'theoutet rwhich. is in a finely .finished'stateescapes; without being subjected to'an undue additional heating which tends .to,spoil it; whereas the portions of-the .raw material lwhichare more recalcitrant to'lhydration andrequire "morelime are retained until hydration is substantially "completed. Stirring occurs of a minimumamount lot the unhydratable portions, which are near the-bottom. This is ,an advantage, since no more than a necessary amount of stirring'should occur in;.these; portions ;to prevent forcing them. up into the; good hydrate which is above. The gateSS is adjusted so that the level ,L is at an optimum value for obtaining a maximum amount ofbest product. The result-is not only a. better hydrated lime: but, by .means of. the invention, a greater percentage of hard hurned materialis' converted. When .core .and other.unhlydratable material is: present, such as..is-,granular, it accumulatesandis'removed at gate 89in timed periods; dictated by. the rate of accumulation, this being *from oneto eight hours.

During the above-mentioned circulatiouandrhydratron, a large amount of steamand somedustare evolved. Theseare drawn on by the induction blower 103,. freshair acting as a :coolant; entering the openings, such as 43 and 83 and of course. at any other points .of infiltration :or:leakage.into the .co'ntainerl. The entrylofvthis cool airprovides a controlled. atmosphereatlevelL for preventing. overheating. Moreover, steam .and-dust .-are drawn off and subjected to the .eold ,water. spray. at nozzle '107. "The blower 103 thoroughly. intermixes this spray with. the steam and dust. Thedust. isentrapped with the condensate, while air"and..the..remaining.steam may leave theexhaust-pip 97-.to,.l.-the .extentithatthe damper] 99 is .open. -In..the outsideatmosphere the .steam. is harmless, whereas if it were to. escape .in..the environs of the container 1 it would constitute n an e- The' result is. that anyppartrofx the product 50 The dust-laden condensate may be sent to waste or is transferred over pipes110 to'the nozzles"56','"'55 and 112 for supplying preheated rmoisture. Under some, al-

though not all circumstances, it may be desirable to 5 apply additional moisture to the granulated material on the bottom 9, 11 without applying additional moisture to the flocculent material inrthe region of the level L. in this event line 112 may be closed at valve 127 and the damper-.99 adjusted. toward closed. position, thus forcing air and any noncondensed steam back through pipes 121 *and-into-theopenings 125. This steam supplies additional water hydration precisely where needed,

i. e., inthe bottom of, the container 1.

Advantages of the invention over-both prior batch and 15 continuous typc hydrators are as follows:

(1) The device has the classifying feature whereby the finely divided dry finished hydrated part of the product is advanced or floated to the outlet, while themore granular unfinished and heavier parts are retained and "recycled-'until'properly finished, rorejected to Waste. In

other words, the. parts vof-the :raw material-which can-be "quickly finished'are promptly removed from the process,

whereas-those parts which require more timeflfor finish- -ingarea-retained. Mereoverfithose parts thatcan prac- *ticallymever be-"finished can be removed through the separatedischarge 89. The result is a greater production -rateof better hydrated limefrorn any type of raw mate- *-'rial"(quicklime) I (2) The:-controlled"atmosphere and recirculation of air-ivaporrmixture *to' the bed has the i further action of controlling the"vapor'absorption'and vapor supply, using air in its relativeand'controllable'amountras an inhibiting medium.

' (3)"The'preheating'ofwaterto 'the premixer initiates amorerapid prehydration.

n (4). The wetxlust collector system with the positive induction"meanstoripreventing escape of steam around the container 1 reduces the nuisance, health and accident hazards ordinarily associated with equipment of this type,

40 and recovers all ofjthedust'which is the besthydrate.

('5)" The controlled atmosphere. and recirculation of air-vapor mixture'to" the -.b'edy mentioned under advantage (2), is easily ohtai'ned'by'control of the damper 99. When this damper isclosed, alarger proportion-of steam enters. the pipes125i-beeause the fan1tl3 is incapable of introducing muchv airinto .the circulating system under such conditions. When; the: damper 99 is opened, then moreain is -.in circulation .and a larger proportion of air .is-.-available,at.ports.125. I'This. control is an advantage, -sincelit ,issometimesas important .to. inhibit. the hydrat- .;ing..actio1ilby...introducing. a substantiahamount of air .Lintothei hydrating-lime, which has a binding. effect, pre- .veutingan; excessive .rate .of hydration. As a: large proportionot. air. is'. introduced "at 125, the reaction is. inhibited, ,.res'ulti ng in lower. capacityabut. a betterhydrate for..certain purposes, although. not necessarily for others. ".Thuslplasterers demand a, special plastic hydrate which is better formed at axlowerreaction rate. Another fea- .ture.in.this connection is'that the single fan 103 is capable of .elfecting .the. desired circulationnand with a simple damper 99 .there-isobtained a: regulation of the-air-stcam proportions.

.,.In view.of-..the above; itwill bezseen that. the'sevcral lobjectswof :the. invention areachieved and other advan- 5 .tageous results attained.

-.As various-changes.couldbe. made in the above constructions Withoutdeparting from the scope of the-in- --vention, it.-.is' intended that all matter -contained in the above description- ;or I shown in; the accompanying drawingsshall-@beinterpretedas illustrative and not in a limitaingsense.

-, lclaim:

1. A hydrator for-:lirne andi'the. like-comprising a conv.tainer having a bottom-and a higher outlet for hydrated material; inlet means for introducing granulated mate- -rial;and water--into said container, and a'rotor in the container, havingadepending baffies eachformed: to surround the center of rotation,'said bafiles having elevated passage, meansfor radiallyiforwardinglighter hydrated -particels= toward said outlet .and .allowing the sinking between-.bafiles of heavier :nonhydrated particles toward the bottom,.said hailiesuhaving lower edges spaced from said .bottompandr inwardly acting Y plowing means connected with some of said lower edgesand adapted to push heavier 8;; nonhydrated particles that are at said bottom toward the 6 center of rotation of the rotor, whereby said heavier parterial and water into said container, said container havticles are recirculated forlonger treatment than said lighter ing a bottom which on its outside is peripherally subparticles. stantially conical and which forms a downward and in 2. Apparatus made according to claim 1, including a ward slope so as to form a central sump, a rotor in the premixer in said inlet for the granulated material and container having depending circular and concentric baflle water, a wet dust collector means for abstracting alr, plates, the innermost baflie plate extending toward the dust and steam from said container and delivering it to sump, said plate being unperforated and carrying at its said collector means for introducing a water spray into lower end outward PIOWIII" elements in t e sum the said abstracting means to wet the dust and condense remaining baffle plates having elevated perforations and some but not all of said steam, including means wherein 10 carrying at their lower ends inward plowing elements water including condensate from the collector is introadapted to push material down said slope. duced into said premixer, and including means for re- 7. Apparatus made according to claim 6, including turning air and uncondensed steam in regulatable propormeans in said container providing a periodically operttons from said collector to the bottom of said container. able waste-material outlet in said sump.

3. A hydrator for lime and the like comprising a cirl5 8. pparatus made according to claim 7, wherein said cular container having a peripherally located elevated waste-material outlet is located between groups of out- I outlet for hydrated material, means for introducing granu- Ward and inward plowing elements. lated material and water into said container, said con- 9. Apparatus made according to' claim 8, wherein the tainer having a conical bottom sloping inward and downmeans for introducing granulated material and water into ward toward its center, a rotor in the container having the n in i constituted y means located in h a depending circular baflie plates above said conical bottom, position on the top of the container as to insert material said bafile plates having elevated passage means for radiat a locatlon also between groups of Outward and Inward allay spaced plow means on their lower edges adapted to References Cited in the file of this patent in uence movement of granules down the conical bottom toward the center of rotation to induce a recycling action UNITED STATES PATENTS in respect to heavier less-hydrated particles. Number Name Date 4. Apparatus made according to claim 3, wherein said 1,668,924 Schaffer May 8, 1928 container has a waste discharge outlet in its bottom ad- 1,780,821 Henderson Nov. 4, 1930 jacent the center of rotation. 1,896,180 Llndequlst Feb. 7, 1933 5. Apparatus made according to claim 4, wherein said 1,929,591 Kun z Oct. 10, 1933 ieilevateid oFtlet din the container has an adjustable over- 2,199,847 Bryson May 7, 1940 ow e ge or a justment of the level of material therein.

6. A hydrator for lime and the like comprising a cir- FOREIGN PATENTS cular container having a peripherally located outlet for Number Country Date hydrated material, means for mtroducmg granulated ma 135.172 ea rita n May 20, 1920

Claims (1)

1. A HYDRATOR FOR LIME AND THE LIKE COMPRISING A CONTAINER HAVING A BOTTOM AND A HIGHER OUTLET FOR HYDRATED MATERIAL, INLET MEANS FOR INTRODUCING GRANULATED MATERIAL AND WATER INTO SAID CONTAINER, AND A ROTOR IN THE CONTAINER HAVING DEPENDING BAFFLES EACH FORMED TO SURROUND THE CENTER OF ROTATION, SAID BAFFLES HAVING ELEVATED PASSAGE MEANS FOR RADIALLY FORWARDING LIGHTER HYDRATED PARTICLES TOWARD SAID OUTLET AND ALLOWING THE SINKING BETWEEN BAFFLES OF HEAVIER NONHYDRATED PARTICLES TOWARD THE BOTTOM, SAID BAFFLES HAVING LOWER EDGES SPACED FROM SAID BOTTOM AND INWARDLY ACTING PLOWING MEANS CONNECTED WITH SOME OF SAID LOWER EDGES AND ADAPTED TO PUSH HEAVIER NONHYDRATED PARTICLES THAT ARE AT SAID BOTTOM TOWARD THE CENTER OF ROTATION OF THE ROTOR, WHEREBY SAID HEAVIER PARTICLES ARE RECIRCULATED FOR LONGER TREATMENT THAN SAID LIGHTER PARTICLES.

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